Hello, I have a few character whom I have created and hopefully developed throughout the past so many years. Though, I'm now coming to the conclusion that I can't truly pick an … arch-type for them, or something of the sort. So, my reason for being here is already stated in the title, but to clarify again, I am looking for help identifying and placing my characters into arch-types.
Help is appreciated with what I asked. However, what is not asked for is criticism of the characters, they have their flaws and, of course, are always under construction.

Characters:

Walter:
He is a sadistic masochist who has a wonderful inferiority complex. He is aware of the actions he does, meaning he knows that some of the things he does aren't actually … quite that good in nature. But he still does them anyways. He is strong and he is smart, he gets his way with anything in the end and doesn't care who he hurts. So long as he proves to himself that they are weaker than him and not as superbly intelligent.
With all that said, he absolutely cannot stand the idea of losing, anything. And any of his rages and outbursts stem from his complex, the anger and fear of losing to another.

Kitten:
Now she is an interesting case, similar to Walter in a few aspects, though she has a very different mind and would much adore the thought and image of him six feet under. With a tragic and abusive past Kitten grew to be what can usually be called a strong woman. Her heart becomes passionate and fluttery at the sight of happy women, specifically without men. With that mentioned, Kitten has chosen to blame all the sorrows -- in the world on men.
She genuinely cares about women and sincerely enjoys seeing them happy. Kitten wants the best for them all, and she is the one to lead them down the path to happiness, along with her faithful followers who have gathered around her throughout the years of her slaying men.
Her one true belief is that if she wiped the world clean of most men (she is not foolish enough to believe they could continue procreating without some, at least) it would become pure. She refuses to believe that her idealism’s are wrong, because if they were, her whole being would crumble around her. So she clings to the idea that she is justice, and she will bring about peace through the slaughter of all men, in vengeance for the wronged women of the world, and the suppression that she still sees – imagined or otherwise.

Leon:
Leon doesn't have too much to him that I'd like to tell, because he is more lengthy than the others. He too has been wronged in the past, but unlike the others, he's still finding his path. He doesn't go out of his way to help others, but if he sees something he thinks is unfair, he may step in to stop it. Depending on if he thinks he can, because he still holds the belief that he is not strong enough to help anyone.
Likewise, he doesn't go out of his way to hurt anyone, but if people rub him the wrong way, or he's being held back from something he believes important to himself, he doesn't hesitate to harm people, even innocent passersby. He realizes this, and sometimes regrets it, but he's still learning, and has yet to solve the question of what's right, and what's wrong.

Celia:
Celia, I already know, is a general bad guy. She enjoys killing, it's a hobby to her, and most of the time, she likes to do it alone. She fancies herself clever, though she isn't terribly more-so than most. The trick with her is that she WILL kill for a fee, if payed enough. When she is or isn't killing for a fee, or just her own enjoyment, she likes to take her time with it, and get as much out of it as possible. She seduces men into dating her, and may even become a sort of call girl for them. She gets them to take her out on dates and buy her expensive things, targeting the wealthy, while tediously making sure she has little to no known connection with them. When she's done using them, she takes her time strangling them to death, and may even have a little fun with it. Not necessarily going for lengthy torture, but more making a game out of it like a cat.
I am not sure if she would fall into the Black Widow category, because she does not marry the men to inherit anything of theirs, and she does not associate herself with them in any way that could be traceable to collect insurance funds.

I'm afraid I'm gonna have to come in and third the not needing to pigeonhole your characters into archetypes thing.

It's somtimes nice to have that if you want an easy time explaining your characters to other people, but really? There's no need. Ultimately there comes a point where this kind of character "development" is actually just a form of procrastination (and I say this as a person who has drawings and pages of biographies for some characters in various novels I'm working on).

Don't worry about trying to find a category for your characters, or trying to make them resemble other characters, or give them theme tunes or mood boards or write interviews with them etc. Get your framework for them laid out and then write the first draft. That'll tell you who your characters are, and then you alternate rounding them out with redrafting your story until you are satisfied with both.